title: Carbon dioxide inhalation as a human experimental model of panic: the relationship between emotions and cardiovascular physiology.
abstract: Inhaling carbon dioxide (CO2)-enriched air induces fear and panic symptoms resembling real-life panic attacks, the hallmark of panic disorder. The present study aimed to describe the emotional and cardiovascular effects evoked by inhaling CO2, taking shortcomings of previous studies into account. Healthy volunteers underwent a double inhalation of 0, 9, 17.5, and 35% CO2, according to a randomized, cross-over design. In addition to fear, discomfort, and panic symptom ratings, blood pressure and heart rate were continuously monitored. Results showed a dose-dependent increase in all self-reports. Systolic and diastolic blood pressure rose with increasing CO2 concentration, whereas heart rate results were less consistent. Diastolic blood pressure and heart rate variation correlated with fear and discomfort. Based on this relationship and the observation that the diastolic blood pressure most accurately mimicked the degree of self-reported emotions, it might serve as a putative biomarker to assess the CO2-reactivity in the future.
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, European Graduate School of Neuroscience (EURON), P.O. Box 616, 6200 MD Maastricht, The Netherlands. Electronic address: nicole.leibold@maastrichtuniversity.nl.
authors.forename: Nicole K
authors.initials: NK
authors.lastname: Leibold
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Viechtbauer
authors.forename: Liesbet
authors.initials: L
authors.lastname: Goossens
authors.forename: Klara
authors.initials: K
authors.lastname: De Cort
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Griez
authors.forename: Inez
authors.initials: I
authors.lastname: Myin-Germeys
authors.forename: Harry W M
authors.initials: HW
authors.lastname: Steinbusch
authors.forename: Daniël L A
authors.initials: DL
authors.lastname: van den Hove
authors.forename: Koen R J
authors.initials: KR
authors.lastname: Schruers
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D001794:Blood Pressure / Q000187:drug effects*; D002245:Carbon Dioxide / Q000009:adverse effects*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004644:Emotions / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D016584:Panic Disorder / Q000139:chemically induced; D057566:Self Report; D013223:Statistics as Topic; D064232:Visual Analog Scale; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide
keywords: Anxiety; Blood pressure; CO(2); Fear; Heart rate